SLIPPERY ROCK — A 28-year-old Harrisville man whose body was found Wednesday night laying in snow may have died of hypothermia, authorities said. Aaron L. Cook had no pulse or other vital signs when his body was discovered about 8:20 p.m. in the area of Copper and Elm streets, investigators said. There was no immediate sign of foul play and investigators have not ruled out the death being accidental, state police said. Police Cpl. Daniel Herr said one possible theory is that Cook passed out hours earlier after a night of drinking and fell where his body was found. “We believe he was drinking heavily,” Herr said. Police suspect Cook may have remained outside in subfreezing and at times below-zero temperatures — without a coat — for as long as 19 hours. An autopsy is planned and police hope the findings, which will include toxicology reports, will determine a cause of death. Investigators believe Cook left home sometime Tuesday night. He apparently met with others to drink in Slippery Rock. Police say Cook was last seen alive about 1 a.m. Wednesday. When he did not return home, Cook’s wife called friends and acquaintances to help search for him. The family did not contact police or other authorities until his body was found.